Answer:
<em>249 kJ</em>
Explanation:
To obtain the energy change of the reaction:
H₂O → H₂ + ¹/₂ O₂
It is necessary to obtain the difference between bond energy of the products and bond energy of the reactant, thus:
Energy of products:
1 mol of H-H bond × 436 kJ/mol = 436 kJ
¹/₂ mol of O=O bond × 498 kJ/mol = 249 kJ
Energy of reactant:
2 mol of H-O bond × 467 kJ/mol = 934 kJ
Energy change of the reaction is:
934 kJ - (436 kJ + 249 kJ) = <em>249 kJ</em>
<em></em>
I hope it helps!
According to octet rule element has eight electrons in its valence shell.This give it the same electronic configuration as a group 18 elements.Atom with electronic configuration 1s2 2s2 2p1 require five electrons to achieve octet. This is because the valence electrons are 3 in 2s2 and 2p1 and hence require 5 electrons to be filled.
Answer:
C
Explanation:
OH- = 1 X 10^-14 / 1 X 10^-5
= 1 X 10^-9
Answer : The age of the artifact is,
Explanation :
Half-life = 5715 years
First we have to calculate the rate constant, we use the formula :
Now we have to calculate the time taken to decay.
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = time taken by sample = ?
a = initial activity of the reactant = 58.2 counts per minute
a - x = activity left after decay process = 42.8 counts per minute
Now put all the given values in above equation, we get
Therefore, the age of the artifact is,
Answer:
one bond between nitrogen and hydrogen and a double bond between the nitrogen atoms.
Explanation:
H-N=N-H